Photocatalyzed C3-H Nitrosylation of Imidazo[1,2- a]pyridine under Continuous Flow and External Photocatalyst-, Oxidant-, and Additive-Free Conditions

Huijie Qiao; Kun Zhao; Xilin Zhu; Xiaoxu Xu; Shixing Wang; Liting Yang; Chunyang Wang; Lulu Zhong; Baiwei Ma; Dehong Yang; Peizhi Xing; Guoqun Liu; Mingli Jiao

doi:10.1021/acs.joc.4c00173

Photocatalyzed C3-H Nitrosylation of Imidazo[1,2- a]pyridine under Continuous Flow and External Photocatalyst-, Oxidant-, and Additive-Free Conditions

J Org Chem. 2024 May 16. doi: 10.1021/acs.joc.4c00173. Online ahead of print.

Authors

Huijie Qiao^{1

2}, Kun Zhao^{1

2}, Xilin Zhu¹, Xiaoxu Xu¹, Shixing Wang¹, Liting Yang^{1

2}, Chunyang Wang¹, Lulu Zhong¹, Baiwei Ma^{1

2}, Dehong Yang¹, Peizhi Xing³, Guoqun Liu¹, Mingli Jiao¹

Affiliations

¹ School of Materials and Chemical Engineering, Zhongyuan University of Technology, Zhengzhou 450007, P. R. China.
² Henan Key Laboratory of Functional Salt Materials, Center for Advanced Materials Research, Zhongyuan University of Technology, Zhengzhou 450007, P. R. China.
³ Henan Bio-based material Industry Research Institute Co., LTD, Puyang 457001, P. R. China.

PMID: 38753574
DOI: 10.1021/acs.joc.4c00173

Abstract

This study reports a protocol for the highly regioselective photocatalyzed C-H nitrosylation of imidazo[1,2-a]pyridine scaffolds at the C3 position under a combination of visible-light irradiation and continuous flow without any external photocatalyst. This protocol involves mild and safe conditions and shows good tolerance to air and water along with excellent functional group compatibility and site selectivity, generating various 3-nitrosoimidazo[1,2-a]pyridines in excellent yields under photocatalyst-, oxidant-, and additive-free conditions.Notably, the proposed nitrosylation reaction, which introduces the chromophore NO into imidazo[1,2-a]pyridine scaffolds, occurs efficiently under visible-light irradiation without any additional photocatalyst owing to the intense light-absorption characteristics of the nitrosylation products. This study could guide future studies on the development of green organic-synthesis strategies with a wide variety of potential applications.